Evaluation on Physicochemical Properties and Antioxidant Capacity of Two Iranian Jujube (Ziziphus jujuba Mill.) Cultivars

Jujube (Ziziphus jujuba Mill.) is an important medicinal plant in Iran. Jujube fruit contains amino acids, polysaccharides and microelements.Ripened jujube fruits were collected at fully mature stage from two research collection of jujube at Khaf and Birjand centers in south Khorasan province, Iran, early in September, 2015.The physicochemical properties and antioxidant capacity were investigated. The antioxidant activity was determined by free radicals (DPPH) scavenging method. The results were showed a significant difference between evaluated physicochemical parameters. The acidity and pHofKhafjujube were 0.72%, 4.37 and the acidity and pH of Birjand jujube were 0.37%, 4.65; respectively. Protein, fat, fruit moisture and vitamin C in Khaf jujube (3.92%, 0.72%, 0.75% and 137.59 mg/100gr fresh weight) were more than Birjandjujube(3.24%, 0.4%, 0.06% and 125.11mg/100gr fresh weight). Birjand jujube had more reducing sugars percent (35.93 %). Seed’s moisture, 100-grain weight and the antioxidant activity of Birjand jujube (0.156%, 151.03 mg, Ec50= 0.1704 mg/ml) was higher than Khaf sample (0.11, 103.06, Ec50= 0.3135 mg/ml). The viscosities of two jujube varieties werein shear thinning fluids category. The viscosity of Khaf jujube sample was higher than Birjand jujube in different durations and shear rates. The transparency of the color of the Birjand sample (18.21%) was higher than Khaf jujube (17.67%). Overall, thebased on sensory evaluation, physicochemical and consistency properties ofKhaf jujube were more suitable than Birjand jujube while the antioxidant activityofBirjand jujube was higher than Khaf sample.